Synthesis of polyunsaturated constituents of phenolic lipids
摘要:
The diene, (ZZ)-[(8,11)-pentadecadienyl]salicylic acid, (or 2-hydroxy-6-[(ZZ)-pentadeca-8,11-dienyl]benzoic acid), has been synthesised by two routes. In the first, the key intermediate methyl or ethyl 2-hydroxy-6-(7-bromoheptyl)benzoate has been converted to methyl or ethyl 2-hydroxy-6-(10-hydroxydec-8-ynyl)benzoate and thence by reaction of the corresponding bromide with 1-pentynylmagnesium bromide to methyl or ethyl 2-hydroxy-6-(pentadeca-8,11-dienyl)benzoate. Selective reduction afforded methyl or ethyl 2-hydroxy-6-[(ZZ)-pentadeca-8,11-dienyl]benzoate. An attempt to employ the Grignard reagent from methyl 2-methoxy-6-(non-8-ynyl)benzoate and reaction with 1-bromohex-2-yne was ineffective because of a side reaction of the former with ethylmagnesium bromide to give a ketone. In the third approach ethyl 2-methoxy-6-methylbenzoate was alkylated with 1-iodotetradeca-7,10-diyne and the product selectively reduced as before to the O-methyl ether ethyl ester. A variety of C-14 intermediates has been prepared for the derivation of the 8(E), 11(E), 8(E), 11(Z) and 8(2), 11(E) stereoisomers by the alkylation procedure. A similar methodology of alkylation can be adopted for obtaining corresponding trienes in which some progress has been made commencing with the synthesis of the 8(2),11(2),14 compound. (C) 1997 Elsevier Science Ireland Ltd.
Borohydride catalyzed redistribution reaction of hydrosilane and chlorosilane: a potential system for facile preparation of hydrochlorosilanes
作者:Yi Chen、Liqing Ai、Yongming Li、Caihong Xu
DOI:10.1039/d0ra03536j
日期:——
Various borohydrides were found to catalyze the redistribution reaction of hydrosilane and chlorosilane in different solvents to produce hydrochlorosilanes efficiently and facilely. The redistribution reaction was affected by solvent and catalyst. The substrate scope was investigated in HMPA with LiBH4 as catalyst. A possible mechanism was proposed to explain the redistribution process.
Facile preparation of hydrochlorosilane by alkali metal halide catalyzed Si-H/Si-Cl redistribution reaction
作者:Yi Chen、Yongming Li、Caihong Xu
DOI:10.1016/j.tetlet.2020.152235
日期:2020.10
Various alkali metal halides were found to catalyze the Si-H/Si-Cl redistribution reaction in different polar solvents efficiently. The scope of silane substrate was studied using KF as catalyst and 18-crown-6 as cocatalyst in DMI. The alkali metal halides catalyzed redistribution system provides a useful method to prepare hydrochlorosilanes more facilely. A possible mechanism was proposed to explain
Combination of 2-substituted carbapenems with dipeptidase inhibitors
申请人:Merck & Co., Inc.
公开号:US05071843A1
公开(公告)日:1991-12-10
A combination of a carbapenem of the formula: ##STR1## where R is H or CH.sub.3 and R.sup.1 is ##STR2## with a renal dipeptidase inhibitor is disclosed.
Oxindole compounds and their uses as therapeutic agents
申请人:Chafeev Mikhail
公开号:US20070105820A1
公开(公告)日:2007-05-10
This invention is directed to oxindole compounds that are useful for the treatment and/or prevention of sodium channel-mediated diseases or conditions, such as pain. Pharmaceutical compositions comprising the compounds and methods of using the compounds are also disclosed.